Java tutorial
/** * (c) Copyright 2013 WibiData, Inc. * * See the NOTICE file distributed with this work for additional * information regarding copyright ownership. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.moz.fiji.hive.utils; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.DataInputStream; import java.io.DataOutputStream; import java.io.IOException; import org.apache.commons.io.IOUtils; import org.apache.hadoop.io.Writable; import org.apache.hadoop.io.WritableFactories; /** * Convenience classes for serializing/deserializing Writable objects into byte[]s. */ public final class ByteWritable { /** * Utility class cannot be instantiated. */ private ByteWritable() { } public static byte[] serialize(Writable writable) throws IOException { ByteArrayOutputStream out = new ByteArrayOutputStream(); DataOutputStream dataOut = null; try { dataOut = new DataOutputStream(out); writable.write(dataOut); return out.toByteArray(); } finally { IOUtils.closeQuietly(dataOut); } } public static <T extends Writable> T asWritable(byte[] bytes, Class<T> clazz) throws IOException { T result = null; DataInputStream dataIn = null; try { result = (T) WritableFactories.newInstance(clazz); ByteArrayInputStream in = new ByteArrayInputStream(bytes); dataIn = new DataInputStream(in); result.readFields(dataIn); } finally { IOUtils.closeQuietly(dataIn); } return result; } }